Nuovo approccio per l'analisi del liquido seminale: comparazione tra metodo manuale e automatizzato.

Semen analysis is the basis for the assessment of male reproductive organ function and infertility. In this study an automated technique of semen analysis is investigated and results are compared with those obtained with the standard manual approach. The considered parameters include sperm concentration, sperm concentration in the total volume of ejaculate, motility as progressive, non progressive and immotile spermatozoa, and typical morphology. The total testing time and the number of operators needed to perform the analysis is also evaluated with both manual and automated systems. World Health Organization has defined some rules to standardize the semen analysis but human errors are somewhat unavoidable and may be associated with incorrect counting and a lesser respect of protocols. In this context an automated method would have the advantage of standardization of the procedures and the results. Overall 132 semen samples are included in the analysis. All specimen have a sperm concentration >2 million/mL. Exclusion criteria are samples intended to cryopreservation, DNA fragmentation and sample with a sperm concentration <2 million/mL. Semen samples are collected by masturbation in a sterile container in a room near the laboratory; each sample is analyzed first with manual analysis and then with automated SQA-Vision system. Spermiogram testing starts from the macroscopic analysis for the evaluation of volume, state of liquefaction, appearance, viscosity and pH of the semen. These steps are the same both for manual and automated assessment. Microscopic analysis includes the visualization of a microscope slide for the search of sperm agglutinates and aggregates. In the manual approach sperm concentration is evaluated at microscope with an eyepiece reticule with grids called Makler chamber. Counting the spermatozoa the operator distinguishes among progressive motile spermatozoa, non progressive and immotile. The operator should count about 200 spermatozoa and it is suggested to do more than one count with different operators. Final step is the evaluation of the typical morphology of spermatozoa, defining as “typical” those with dimension of head, midpiece and tail within the range of normal values. In the manual procedure the study of morphology requires different steps of fixing and staining of semen sample in a microscope slide. SQA-Vision is an automated system of semen analysis based on the principle of electrooptical signal processing in combination with built-in computer algorithm. The system analyzes the sample through a testing capillary which have a cuvette section that is filled with sperm sample, then is inserted in the measurement chamber and results about sperm concentration, sperm concentration for ejaculate, percentage of progressive, non progressive motile and immotile spermatozoa, percentage of typical sperm morphology will appear in about 75 seconds. An optical density detector measures the amount of light absorbed by the sperm cells and converts it to optical density (OD). Sperm cell motility is analyzed in the thin section of the capillary as they move through a light beam in the system: the movement of mobile sperm cells causes light disturbances that are converted into electronic signals with “peaks and valleys.”The comparison analysis shows that the results obtained with the manual and automated assessment are correlated for all parameters, they are less correlated for values inferior to 5°percentile indicated by WHO. On the other hand, the workflow analysis allows us to point out the advantages of the automated system both in terms of time savings and of the reproducibility of data. However, the standardization of the total processing time may become advisable in high-throughput laboratories where most healthy men undergo the semen fluid analysis as a screening test, while for patients who present clinical manifestations the adoption of manual analysis could be suggested.